Beside this, what is negative z direction?
With the usual orientation of the x-y plane: the positive z direction points out of the page towards you and the negative z direction points into the page away from you.
One may also ask, is z the vertical axis? The z-axis is vertical and the x-axis is highlighted in green.
Then, what is XYZ position?
The Y axis refers to vertical position (perpendicular to the base) and the X axis refers to the horizontal position (parallel to the base).
What directions are XY and Z?
From that point, the world X, Y and Z axes extend. In Maya, X is the axis that goes side to side, Y is up to down and Z is forward to backward (in some other 3-D applications, Y and Z are flipped).